CN102667132A

CN102667132A - Electric heater, heating device and heating system

Info

Publication number: CN102667132A
Application number: CN2010800499289A
Authority: CN
Inventors: M·佐泽托; A·巴尔巴诺; P·克隆博; M·阿拉塔
Original assignee: Eltek SpA
Current assignee: Eltek SpA
Priority date: 2009-11-06
Filing date: 2010-11-02
Publication date: 2012-09-12
Anticipated expiration: 2030-11-02
Also published as: CA2779367A1; EP2496821A1; ITTO20090853A1; US9638152B2; WO2011055295A1; BR112012010485A2; EP2496821B1; CN102667132B; IT1396306B1; US20120224839A1; CA2779367C

Abstract

The invention relates to an electric heater (5A, 5B) for fuel of endothermal engines, in particular for fuel systems called "common rail" and the like. The heater comprises a heating part and a terminal (8B) adapted to be associated with one end of the hollow body (2) of a fuel feeding duct (1); advantageously, the terminal is at least partly made of plastic material. The invention also relates to a fuel feeding duct to which said heater is applied, as well as to a fuel warm-up device.

Description

Electric heater, heating equipment and heating system

Technical field

The fuel-feed conduit that the present invention relates to electric heater, fuel preheating device and be used for the heat absorbing type motor.

Background technique

As everyone knows, in internal-combustion engine, the mixture of fuel and fuel agent is (this firing chamber is included between cylinder and the piston) internal reaction in the firing chamber, so that begin to produce mechanical work from the chemical combustion reaction.

Term " fuel " is meant oxidized chemical substance or mixture, and term " fuel agent " is meant chemical substance or the mixture that between the chemical combustion stage of reaction, is reduced.Usually, natural fuel is not fully pure, comprises additive (this additive can be subparticipation or not participate in combustion reaction) usually; And it (is the mixture of multiple gases that actual fuel agent is generally air; Wherein a kind of, promptly oxygen is participated in combustion reaction); But, for the present invention, term " fuel " will only be meant liquid or fluid, for example gasoline, diesel oil, alcohol or fuel oil, and it mixes with fuel agent, so that produce combustion reaction, and no matter whether it comprises the part of any additive or said fuel agent.

In order to promote burning (fuel quantity that uses about reality and the reaction uniformity of in the firing chamber, carrying out) and to minimize harmful toxic emission and attempt to make efficient maximum, become known for getting into the firing chamber scheme of this fuel of preheating before at fuel.

This measure also is used to handle following two problems:

Burning under each working state of-optimization motor;

-make things convenient for cold starting.

When fuel is diesel oil (as in DENG) or biofuel or alcohol (ethanol that is for example obtained by the victual fermentation a, country of this fuel that is widely used is Brazil) or fuel oil, can feel these problems especially.

Also some motors of considered are designed to be used in more than one fuel type; Two kinds of different fuel types (for example gasoline and alcohol) particularly: in these motors; Two kinds of fuel can be used alternatingly, and therefore may occur that, wherein; A kind of fuel requirement preheating, and another kind does not need or the preheating of the littler degree of needs; Perhaps they can be used as mixture according to the predetermined and/or variable ratio of said two kinds of different fuels; Mixed processing can be carried out automatically, and ratio or percentage are confirmed by the electronic control unit of vehicle.

In prime mover industry; Current widely used technology is so-called " rail altogether " or " fuel rail "; It comes down to a kind of like this ejecting system; Wherein, fuel is supplied to very high pressure through single feed conduit, and this single feed conduit is given a plurality of cylinders (therefore definition " rail altogether " and " fuel rail ") charging.

Between the firing chamber of " rail altogether " or " fuel rail " and cylinder, sparger is arranged; This sparger can directly be connected with feed conduit; Perhaps be connected with this feed conduit, usually, single feed conduit arranged for whole motor through the very short conduit that divides expenditure from feed conduit self.

For the motor that is equipped with " rail altogether " or " fuel rail " (being feed conduit); Proposed multiple different schemes come in the fuel supply firing chamber before this fuel of preheating: according to first kind scheme, fuel preheating in (for example described in patent DE19918227) with the pump of fuel supply feed conduit; According to second type, fuel comes preheating through a plurality of heaters that are installed in single sparger place, and said single sparger is given cylinder charging (for example described in patent WO2006/130938 and DE10340159); According to the 3rd type, fuel comes preheating (for example described in patent WO2007/028663) through the heating ABAP Adapter that is arranged between feed conduit and the sparger.

The scheme of another type is used for when fuel flows through feed conduit, heating this fuel, for example described in the open JP83338339 of patent.The invention belongs to such scheme.In this case, feed conduit is also as actual Preheating unit.

The document has been instructed to above-mentioned purpose and has been used electric heater (those skilled in the art are also referred to as " glow plug "), and this electric heater comprises provides galvanic single electric winding, and it is heated through joule effect.

In order to make winding and the fuel that flows through feed conduit isolate, electric heater comprises the can that surrounds winding, and the sealing shell extends on the whole length of feed conduit basically.

In the device of Japan Patent JP83338339, heater is screwed in the feed conduit through respective threads.

This scheme need be used suitable material, so that the excellent sealing that acquisition is threaded under the high temperature that reaches at work.

And in order direct current to be supplied with the winding of this heater, this winding must be at a side and earth point, a bit connecting of vehicle chassis for example, and be connected in the male of opposite side with the battery of vehicle; Two discrete electrical connections must be provided for this reason.

These two conditions make almost must use metallic material to make feed conduit and electric heater.

In fact, even in sizable hot amplitude (those hot amplitudes that occur in the for example described here Preheating unit), metallic material for example aluminium, steel or other alloy can provide being threaded of stable and sealing.

Therefore, in the described scheme of JP83338339, one (for example ground connection connects) in two electrical connections realizes that through the threaded fittings that is screwed in the metal feed conduit this metal feed conduit must be electrically connected with earth point (the for example part of vehicle) again.

This means restriction to the material of feed conduit (this feed conduit can only by made); And the danger that exists electrical connection to lose efficacy; Because be electrically connected and realize through a plurality of machanical fasteners that are used for different device, thus the danger of the unusual contact resistance that causes connecting with the power supply circuits of heater, and this attracts high electric current usually; Wherein, any unusual resistance increase can be confirmed the incorrect energy dissipation or jeopardize the correct power supply to electric heater.

And the regular fuel of heater housing obstruction that extends along whole feed conduit flows.

The Preheating unit of known another type also, wherein, electric heater or glow plug comprise radiator, and this radiator is made up of slug usually, and this slug preferably has tubular in shape, and is provided with and is used to the hole that allows fuel to get into.

Radiator is arranged through conduction and the state that carries out heat exchange with heater, and this radiator is in the state with the fuel heat exchange again.

But, the shortcoming of this heater and Preheating unit thereof is to have higher thermal inertia, promptly can not the rapid heating heat, and reason is at first to add heat radiator, then this radiator pre-heating fuel again.

And; In this scheme; The hole of radiator maybe since sediments that stays by fuel usually and any dirt that is present in the fuel block, thereby cause the inaccurate flow in the feed conduit and reduce the functional of feed conduit and cause invalid fuel to heat.

Another total problem of the electric heater of existing technology and Preheating unit stems from the high temperature that in being electrically connected the zone, reaches in operation.

In order to prevent to damage, known heater has the structure shown in document JP of being similar to 83338339, promptly has threaded metal ground connection accessory.

The heater of existing technology total also a problem is relevant with such situation, promptly fuel must be heated to the temperature that is lower than vapourizing temperature, so heats is limited: in scheme known in the art, this realizes through control heater on time.

Another total defective is relevant with such situation,, in the scheme of existing technology, can not detect defective control on time that is, and this possibly cause winding overheated and impaired and cause carburretion.

Summary of the invention

The objective of the invention is to overcome these and other defective of existing technology; Particularly through realizing above-mentioned purpose according at least one electric heater accessory claim, that be used for the fuel-feed conduit, this accessory claim will be as the integral part of this specification.

First purpose of the present invention provides a kind of electric heater and/or Preheating unit and/or heating system that is used for fuel; This fuel is used to supply with the heat absorbing type motor; This electric heater and/or Preheating unit and/or heating system can be made economically; And guarantee to improve and reliable performance, and preferably its type is that part is assembled with automated manner at least.

Second purpose of the present invention is to improve the structure and/or the reliability of heater and/or Preheating unit and/or system, so that the power supply attended operation, particularly through taking to allow to use the appropriate action of plastic components.

Another object of the present invention is the appropriate seal that guarantees between each parts of forming heater and/or Preheating unit, make dirt or water not to come in from external penetration, and fuel can not be revealed away from feed conduit.

An also purpose of the present invention provides a kind of inherently safe electric heater and/or Preheating unit, wherein, prevents overheated under failure condition.

Another purpose of the present invention provides a kind of Preheating unit, and it still less receives obstructing problem, and can be with even mode pre-heating fuel.

The invention still further relates to a kind of fuel preheating device, wherein, feed conduit is associated with two electric heaters, the invention still further relates to a kind of such feed conduit.

Description of drawings

Characteristic of the present invention will be set forth in accessory claim especially; To more know said characteristic and thus obtained advantage through following explanation, following explanation will provide through limiting examples with reference to accompanying drawing, in the accompanying drawing:

Fig. 1 is the perspective view according to the heating equipment of first embodiment of the invention;

Fig. 2 is the partial, exploded perspective view according to the heating equipment of first embodiment of the invention;

Fig. 3 is the sectional view of a part of the heating equipment of Fig. 1;

Fig. 4 is the sectional view of the electric heater of Fig. 3;

Fig. 5 is the sectional view of first portion of the electric heater of Fig. 3;

Fig. 6 is the sectional view of second portion of the electric heater of Fig. 3;

Fig. 7 is the sectional view of third part of the electric heater of Fig. 3;

Fig. 8 is the exploded view of the electric heater of Fig. 3;

Fig. 9 has shown the details that couples between the body of the heating equipment of the electric heater of Fig. 3 and Fig. 1;

Figure 10 is the external view of the electric heater of Fig. 3;

Figure 11 is the sectional view of the heating equipment of Fig. 1;

Figure 12 has shown the version of the heating equipment of Fig. 1;

Figure 13 has shown the details of first version of the electric heater of Fig. 3;

Figure 14 has shown second version of the electric heater of Fig. 3;

Figure 15 has shown the details of the 3rd version of the electric heater of Fig. 3;

Figure 16 has represented the details of the 4th version of the electric heater of Fig. 3;

Figure 17 has represented some characteristic sizes of parts of the electric heater of Fig. 3.

Embodiment

Below with reference to figure 1; Shown the external view of the fuel preheating device D that is used for the heat absorbing type motor among the figure, this Preheating unit comprises feed conduit 1, and this feed conduit 1 comprises hollow body 2 again; This hollow body 2 defines feed conduit at least, and fuel flows through this feed conduit; Fig. 2 and Figure 11 have represented exploded view and the sectional view of same heating equipment D.

Hollow body 2 comprises fuel inlet, and by entry port 3 expressions, fuel gets in the internal cavities fuel preheating in this internal cavities through this entry port 3 in the instance that provides in this fuel inlet; This hollow body 2 also has four outlets 4, and a plurality of spargers or branch conduit are pointed in these four outlets.

Certainly, outlet 4 number usually with the number coupling of the cylinder of motor, so can change as required; Therefore, practical application also can be arranged to one, two, three, five, six, eight or multiple exit more.Then, hollow body 2 has two

free end

21A and 21B, and these two

free end

21A and 21B open wide, so that can insert

electric heater

5A and 5B, shown in the exploded view of Fig. 2, therefore this

electric heater

5A and 5B are used as the sealing plug of hollow body 2 again; For this reason,

electric heater

5A and 5B preferably can assemble and/or lock with quick and safe mode.

According to instruction of the present invention, in fact,

electric heater

5A and 5B are configured for the sealing plug of hollow body 2, and preferably are associated with body of air through the shape coupling.

Preferably, shape is coupled as interference fit.

In fact; As show shown in the accompanying drawing 2 and 9 of heater 5B; This heater 5B is assembled among the opening end 21B of hollow body 2; Therefore clog body 2 with simple with mode fast, and do not need the screw thread of any appropriate, therefore can different materials (no matter being plastics or metal) be coupled in together.

The locks in place of heater 5B in fact advantageously through mechanical fastening system for example cotter pin 15B guarantee that this cotter pin 15B is assembled in the groove 28B on the end that is arranged in body 2, and engage, thereby prevent that heater from coming off with heater 5B.

For this reason, also with reference to figure 9, heater 5B comprises and is used for fixing the for example housing 23B of cotter pin 15B of device that this housing 23B also engages with hollow body 2; It is annular or circular seat preferably, is installed in the different amount position thereby be particularly conducive to heater 5B, promptly is used for when heater 5B is assembled to body 2, allowing its rotation or angular motion.

Certainly, those skilled in the art can advantageously use other device, for example wait the dowel that cooperates that heater 5B is fixed on the hollow body 2 with suitable seat.

Should be known in that two

electric heater

5A and 5B are positioned at the opposite two ends of feed conduit 1 and are separated from each other, promptly through convection current (through being full of any fuel of hollow body 2) and the state that carries out heat exchange through radiation (but not through conduction) possibly.

This provides a plurality of advantages: at first; The internal capacity of hollow body is freer than existing technology scheme; Reason is half shorter length of the total length of two

electric heater

5A and 5B ratio of elongation hollow body; Thereby make that the core of body is free, flow to sparger so that help fuel.

And; In this scheme; Between two heaters, do not have connecting element, certainly except the connecting element of the hollow body 2 that is used to install them, therefore avoided because any blockage problem that dirt etc. cause; Avoid (as known case) to use the element that extends the whole length of hollow body simultaneously, this has been avoided the problem in place and that mobile formation hinders to fuel about they secure fixation.

With reference to Figure 11, should be known in that in installment state each

electric heater

5A and 5B comprise electrical heating elements, for example electric winding 62A, 62B.

According to instruction of the present invention, each

electrical heating elements

62A, 62B extend in body 2, and preferably only extend in the zone between two that are used for sparger adjacent outlets 4.

According to a favourable optional feature, each

electrical heating elements

62A, 62B do not extend in arbitrary outlet 4.

The test shows of carrying out in the structure that two

electric heater

5A and 5B are arranged, provides optimum aspect the even heating of the fuel of this scheme in feed conduit.

Particularly, each

electric heater

5A and 5B provide optimum at two adjacent catheters or aspect the even fuel heating that exports 4 in (promptly at these two conduits or export insert respective electrical heater 5A, the electrical heating elements 62A of 5B, 62B between 4).

Also with reference to figure 3 and 4, can know the particular design according to electric heater 5A of the present invention and 5B, should be known in for clear that these figure have only shown

device

5B, 5A is definitely similar for device; Because same cause, following explanation will mainly concentrate on electric heater 5B or concentrate on and can be used for according in the various electric heaters of fuelizer of the present invention and/or heating system at least one; Therefore, represent but project that the back is added with alphabetical A or B must be thought identically that by same reference numerals said letter is meant

electric heater

5A or 5B.

Introduce heater 5B below, it comprises fire end 6B, spacer element 7B and the terminal 8B that couples each other, shown in detailed among Fig. 4 to 7.

Fire end 6B shows in greater detail in Fig. 5; And comprise shell 61B again, and this shell 61B at one end has the tubular in shape of sealing especially, and it holds electrical heating elements in inside; In this example; This electrical heating elements is made up of electric winding 62B, and this electricity winding 62B preferably has the coiled type shape, is suitable for when receiving the potential difference of the end of crossing it, heating through joule effect.In shell 61B inside material 63B is arranged, this material 63B electrical insulation but is good heat conductor, magnesium for example, and the shape of powdered or less compressing grains preferably, it makes winding 62B and shell 61B electrical insulation.

Fig. 5 has also schematically shown the electrical connection of winding 62B, and this is connected electrically in the back will be more in detail introduces, and it crosses two electrodes (between this two electrode, having set up potential difference) and connects at this moment only to need explanation; At this on the one hand, should be known in that shell 61B self is the part of power supply circuits; Reason be make winding 62B be arranged to two electrodes in an electrode; Particularly negative pole or ground connection level electrically contact, and said shell 61B is electrically connected with the end of winding 62B, particularly through welding.

Therefore, winding 61B is by the conductive material manufacturing, and preferably metal is more preferably stainless steel, and for example AISI 303 or INCONEL are so that bear fuel (this winding is immersed in this fuel at work) chemical erosion.

In Fig. 5, can also see the terminal end of the pin 73B shown in Fig. 6, this pin 73B is electrically connected with winding 62B, also is electrically connected with the electric conductor (preferably positive conductor) of terminal 8B.

Electrical connection forms through hard soldering or interference fit etc.

Sell other parts electrical insulation of 73B and electric heater 5B, in deciding for example with hollow lining 72B electrical insulation (this hollow lining 72B will introduce in the back in more detail) electrical insulation, and with respect to shell 61B.

Terminal end through being arranged in pin in pin 73B fixed (this terminal end is opposite with the terminal end that couples with winding 62B) is located decide insulator 77B and encircles 78B through deciding of arranging along the body of pin 73B to obtain; Should be arranged between pin 73B and the shell 61B by fixed middle ring 78B; Preferably at the terminal edge place of shell 61B, so that make their isolate and prevent any short circuit.

Advantageously, in the processing procedure of manufacturing and build-up member, winding 62B (preferably couple and/or be welded on this pin 73B with pin 73B) at first inserts among the shell 61B, is welded on then on the shell 61B; Then, magnesium powder or particle pour in the clearance spaces between winding and shell; This assembly is closed through ring 78B in fixed subsequently, carries out radial forging then and handles, and this reduces diameter and the compacting magnesium of shell 61B, does not have insulator or has the zone that reduces insulator layer so that can not stay.

Should also be appreciated that; When installing; Encircle spacer element and/or insulator that 78B advantageously not only is used as pin and casing wall in deciding, also be used as the fixed middle element in manufacturing and/or assembling stage and be used as stopper, because it prevents that magnesium from coming out when radial forging shell 61B.

Fig. 6 has also represented the zone that couples between shell 61B and spacer element 7B: the inside of this spacer element 7B is local at least hollow; And coupling through being assembled among the spacer element 7B and/or through selectively hard soldering (for example induction or type of laser) between shell 61B and spacer element 7B realizes with making shell 61B interference fit; So that guarantee suitable mechanical and gas tight seal between them; For example be not limited to through hard soldering; Particularly utilize the hard soldering of silver and/or Cuprum alloy, preferably before machinery and/or chemically cleaning are carried out in the surface that will weld.

This couple can through make the terminal end of spacer element 7B be provided with expansion mouth 71B and through make shell 61B to insert in the spacer element 7B end sections a little convergent simplify.

For spacer element 7B, it at length shows in Fig. 6: it comprises hollow lining 72B, i.e. the tubular element of suitable shape, and this hollow lining 72B couples in a side and shell 61B, as previously mentioned, couples at opposite side and terminal 8B.

Hollow lining 72B has two diametral rib 74B in the side towards terminal 8B; These two diametral rib 74B are outstanding from the surface of hollow lining 72B; Particularly radially and/or the form that circularizes outstanding, thereby be formed for the seat 75B of packing ring 10B, this is also visible in Fig. 4.

Packing ring 10B be arranged to that body 2 with spacer element 7B and feed conduit connects and/or closely against outwards reveal from the inside of feed conduit 1 so that prevent fuel.

There is the sealing profile end that couples with terminal 8B of spacer element 7B; Preferably constitute in the example shown by one or more diametral ribs; This diametral rib is outstanding from the surface of hollow lining 72B, particularly radially and/or the form that circularizes outstanding, this will introduce in the back more in detail.

Hollow lining 72B is arranged to the state that electrically contacts with the electric conductor 79B (also as shown in Figure 7, preferably negative conductor or grounding conductor) that is attached to (afferent to) terminal 8b; This electrical connection preferably guarantees (this electric conductor 79B arranges or is bonded on the suitable end or seat of tubular element or lining 72B) by the given shape of electric conductor 79B; And/or guarantee (for example to obtain through hard soldering through corresponding welding; Particularly utilize the hard soldering of silver and/or Cuprum alloy, perhaps electric welding).

The inside of hollow lining 72B has the diameter of differentiation, handles and/or prevent any short circuit so that help assembling; Be more especially, the diameter in the zone of next-door neighbour's flared part 71B is less than the diameter of the remaining part of lining.

For insulator 77B in fixed; Except avoiding any between the 73B of hollow lining 72B and pin electrically contacts; It also advantageously carry out to keep pin 73B with respect to hollow lining 72B the function in fixed, to avoid causing any motion of any short circuit, for example vibration and/or the distortion that causes owing to temperature variation; Preferably, it also provides the thermal insulation of the part of terminal 8B.

Insulator 77B is preferably by stupalith in fixed; For example aluminium oxide or steatite are made, and the hollow lining 72B of spacer element 7B is preferably by for example manufacturing such as steel, stainless steel of metal, and the body 81B of terminal 8B is preferably by the plastics manufacturing; Polyamide (PA) for example; For example PA66 preferably has 30% glass fibre, promptly a kind of nylon.

Also must consider, in working order in, shell 61B possibly reach about 500 ℃-600 ℃ temperature, if do not have hollow lining 72B and/or fixed in insulator 77B, this possibly damage the plastics of terminal 8B.In fact, hollow lining 72B advantageously carries out dual functions: at first, a part of heat that it is produced by winding through dissipating with prevent that terminal 8B from receiving because any infringement that high temperature causes makes terminal 8B and shell 61B thermal insulation; Secondly, its guarantee or help making shell 61B in feed conduit suitable fixed in, like this, it does not receive the influence of the problem relevant with engine luggine basically.

For coupling between spacer element 7B and terminal 8B, it can be realized by different way: for example, the plastics of terminal 8B can be molded on the end sections of lining 72B, thereby obtain a plurality of advantages.

For example, first advantage is to assemble originally with relatively low one-tenth more easily; Appropriate action (said projection 76B for example is provided) also can improve coupling and sealing between two parts; Thereby any leakage that reduces the handing-over between them or couple in the zone is dangerous; Acquisition can guarantee the surface or the seat of better attached between plastic materials and metallic material or sealing, and produces can the be porous longer and winding raod more that prevents between two kinds of materials directly.

In fact; The terminal 8B shown in detail comprises plastic body 81B among Fig. 7; This plastic body 81B preferably is molded on the terminal part of lining 72B; Can porous longer path so that obtain best mechanical seal and be used to prevent, but said porous derives from the respective complementary seat 86B that forms and the joint between the projection 76B being used for that parts of plastics with terminal 8B is molded in the processing procedure on the lining 72B.

Plastic body 81B ends at a 82B in a side; Be used to make it and complementary electrical link or socket to couple; Electric conductor, particularly two electric terminal 83B' and 83B " are arranged among this 82B, as shown in Figure 10; one in the electric conductor must be connected with the ground wire of vehicle, and another is connected with the male of battery.

more stable coupling between the electrical socket that obtains terminal 8B and complementation is provided with fillet 84B on electrical socket, be expressed as with unrestricted form here to be used for the seat that hasp couples tooth, and itself be known type, will no longer introduce.

Pin 73B engages in engaging zones 85B among the plastic body 81B of terminal 8B, particularly after coating mold treatment, coats in the mold treatment at this, and plastic body is molded on the terminal 8B.

Also have the electric contact with conductor 83B' near the engaging zones 85B, it is visible in the exploded view of Fig. 8: conductor 83B' and pin 73B preferably through by welding consumables optionally induction brazing be coupled in together, thereby guarantee extraordinary electrical connection.

Conductor 83B' and 83B " in Fig. 8, show in greater detail, wherein, can know, they comprise be associated with pin 73B and lining 72B respectively couple end 95B' and 95B " and be used for engage free end 96B' and 96B " with the respective electrode (not shown) of electrical socket.

Conductor 83B' and 83B " couple end 95B' and 95B " preferably obtain through shearing and bending flat metal bar, and this flat metal bar is processed to part-circular or semi-circular profile at least.

Said end 95B' and the 95B of coupling is " preferably through obtaining with respect to one of the intermediate portion side extending of electric terminal 83B (95B ") or two (95B') crooked ends.

In more detail; In this limiting examples; Conductor 83B " and the electric contact between the hollow lining 72B is by conductor 83B " " realizes; this end 95B " end of the hollow lining 72B of local envelopment at least through it self end 95B; And conductor 83B' and the contact of pin between the 73B realize that through it self end 95B' this end 95B' is the end of the hollow lining 72B of local envelopment at least by conductor 83B': said contact is preferably again through being fixed by the hard soldering of welding consumables selective thermal, and this also can obtain extraordinary electrical connection in this example.

Like this, preferably, each parts keep fix in position in the processing procedure that is used for molded plastic body 81B, and this further helps making electric contact insulation and fixing.

In Fig. 7, reference number 89B representes therminal retainer, is used for that " extension part along them is held in place with two conductor 83B' and 83B when welding and/or during molded plastic body 81B; But must be pointed out that said therminal retainer 89B is optional.

Said therminal retainer 89B advantageously can be with thermoplastic material, and for example polyphenylene sulfide (PPS) comes molded.

Terminal 8B also comprise two radially or the annular projection or fin 88B; This projection or fin 88B place, the end that engages with hollow lining 72B of plastic body 81B or near outstanding from the surface of plastic body 81B; This fin 88B defines the seat 91B that is used for packing ring 11B (for example O shape ring); In the time of in being installed in body 2; The inwall of the plastic body 81B of this packing ring 11B and terminal 8B and the hollow body 2 of feed conduit 1 connects and/or closely is arranged between them, so that guarantee to prevent the dangerous appropriate seal of outside agent (for example dirt, waste water etc.) infiltration.

Should know; Packing ring 10B and packing ring 11B arrange around metal and the interface region between the plastics of hollow lining 72B and terminal 8B, so that make said interface region and fuel (through the effect of packing ring 10B) and isolate with outside agent (through the effect of packing ring 11B): this scheme can make that interface region remains in the sealed environment.

The most responsive partly (being the interface between metal and the plastics) through with electric heater 5B is sealed in the sealed environment; Can be so that be coupled in together by the parts of these two kinds of different materials manufacturings, can not produce simultaneously maybe be in operation (because different heat expansion coefficient and) forms the zone of leak point and/or break.

This measure helps a part of heat of dissipating and being produced by winding with the existence of lining 72B, therefore allows to use the terminal 8B that is made by plastics, in the prior art because the problems referred to above and can not use such terminal 8B.

Also for packing

ring

10B and 11B, should know that they have two different-diameters: particularly, packing ring 10B has the diameter littler than packing ring 11B.

This diameter difference has been simplified insertion and/or number of assembling steps.

In fact, in number of assembling steps, this two O shapes ring or packing ring 10B all must be widened uniquely, so that be positioned in its seat (the packing ring 11B with larger diameter needn't be broadened so that through being used for the seat of packing ring 10B).

Should also be appreciated that; The said size of said two

packing ring

10B and 11B is different; Particularly; Packing ring or O shape ring 10B has than packing ring or the littler diameter of O shape ring 11B, also for allow said packing ring insert respectively body 2, have in two housings of different-diameter (housing), this is especially for preventing packing ring impaired purpose in number of assembling steps.

In such structure, in fact electric heater 5B can be installed in the body 2, and packing ring must pack body 2 into along short path with interference fit ground in; This means that impaired danger is littler and it is littler that heater is mounted to effort required in the body 2.

Electric heater 5B comprises seat 75B (being used for packing ring 10B) and the 91B (being used for packing ring 11B) with different-diameter, and the diameter of seat 75B is less than the diameter of seat 91B.

To this, should also be appreciated that, with reference to figure 4; Hollow body ends at two different-diameters; In Fig. 4, be expressed as 25B and 26B, the most inboard diameter 25B is less than outermost diameter 26B, so that be formed for assembling two seats of said packing ring or

O shape ring

10B, 11B; Such advantage is provided simultaneously, and promptly packing ring must be along than short path in number of assembling steps.

For the material of packing

ring

10B, 11B, at least one in them can be by fluorinated elastomer, and for example obtainable on the market, name is called the fluorinated elastomer of " Viton " (TM trade mark) to be made, and this is particularly in order to provide better anti-chemical reagent property.

As going back a favorable characteristics; It should be noted that; Each

spacer element

7A, 7B preferably are being protruding to the catheter interior of being confirmed by hollow body 2 in the zone of (near the end of feed conduit 1) outlet 4, and termination immediately across said outlet 4 after basically.

Fire end 6B from the part of spacer element 7B protrusion and shell 61B, wherein arrange partially overlapping of winding 62B: by visible the accompanying drawing, in fact, although shell 61B extends in the inside of hollow lining 72B, winding 62B is replaced by pin 73B in that part of.This provides two-fold advantage: on the one hand; It has guaranteed effective heating (only must cross wall and the electrically insulating material 63B of shell 61B because of the heat that is produced by winding) of fuel; Simultaneously on the other hand, hollow lining 72B can be not overheated, because it does not comprise winding 62B.

For winding 62B, the test display line number of turns N that carries out _SpAnd the ratio between the pitch P (representing among Figure 17) is basically greater than 2, preferably greater than 4.

For example, for number of stitches N _Sp=11.5 with pitch P=2.75, ratio N _Sp/ P=4.2, and for N _Sp=13.5 and P=2.4, N _Sp/ P=5.6.

As its replacement scheme or with its combination, observe, suitable is, < 6mm, preferably < 3.5mm is so that obtain all heating of even well distributed for P for pitch P.

When D outer diameter at cylindrical outer casing 61B _InvLinear diameter D with coil 62 _FilBetween ratio D _Inv/ D _FilIn 3 to 10 scope, in the time of preferably in 5 to 7 scopes, with obtaining best result, particularly aspect the best heat transfer (for pre-heating fuel as far as possible apace) can not hinder fuel mobile hollow body 2 in simultaneously.

For example, for D outer diameter _InvThe shell 61B of=5mm, the linear diameter of coil can be D _Fil=0.9mm, the ratio between them is D _Inv/ D _Fil=5.55; For D outer diameter _InvThe shell 61B of=6mm, the linear diameter of coil can be D _Fil=1.1mm, the ratio between them is D _Inv/ D _Fil=5.5.

For feed conduit, except above-mentioned characteristic, it can also for example have the PA66 (nylon) of 30% glass fibre advantageously by the plastic materials manufacturing, and reason is that it does not need conduction, and these are different with situation of the prior art.

Certainly, the type of plastic materials can change, and for example, electric heater can be to fix with aforementioned different mode.

But, under the situation that does not depart from the scope of the present invention and instruct, those skilled in the art can carry out a lot of other variations.

For example, Figure 12 has represented first version, and wherein, same reference numerals is represented same parts (for the sake of simplicity, they will no longer further be introduced); It is just enough to say so; In this example promptly; Feed conduit 1' has fuel entry port 3', and this fuel entry port 3' is in the center with respect to the longitudinal extension part of conduit 1' self, and feed conduit 1 has such port 3 near an opening side of hollow body 2.

The said version of Figure 12 provides such advantage, it make fuel can more be evenly distributed in feed conduit 1 ' in, and

heater

5A, 5B are littler to the influence that takies the aspect of fuel channel.

Represented an also preferred variation among Figure 13: it has shown the details in the zone that hollow lining 72B and shell 61B couple: in this version, in order to improve sealing between the two, additional isolation device 80 is arranged in the terminal edge place of shell 61B.

Said additional isolation device is an annular insulator; Resin etc. for example, this annular insulator preferably is positioned to the terminal edge around shell 61B, and against the inwall of hollow lining 72B; So that improve sealing between the two, and guarantee to pass pin 73B that its extends more fixed in.

" the seat 82B' of B can be with respect to electric heater 5B' motion, and promptly the electric coupler of heater is equipped with electric wiring, and this electricity wiring is processed by one section cable 50 to have represented another version among Figure 14: in this example, have conductor 83'B and 83; Said cable 50 is preferably such that the conductor 83'B and 83 of a 82B', and " B is electrically connected with pin and the lining of electric heater 5B', and this electric heater 5B' and aforementioned means 5B are similar.

The advantage of this version is, can pack into the at an easy rate engine compartment of vehicle of the feed conduit that is equipped with said Preheating unit is inner, thereby overcomes owing to any restriction that exists dissimilar obstacles or wire harness to cause.

The version of having represented winding among Figure 15.

In this scheme, winding 63'B has two different windings: it is inner and in the closed side of shell from hollow lining protrusion that the 630B of first portion is arranged in shell 61B; Second portion 631B preferably be arranged in shell 61B inner and shell when installation the time be in a side of hollow bush inside.

The first winding part 630B and the second winding part 631B are connected in series each other, and part 631B is PTC (positive temperature coefficient) resistor, and its resistance increases with temperature.

Through the said resistor of suitable selection; Can advantageously limit any superheat temperature with basic automated manner; And control without any need for electron feedback: in fact; When fault etc. makes that temperature surpasses the preset limit temperature, the resistance of part 631B will increase, thereby reduce the heating of joule effect and (therefore) part 630B.

As a version also, at least a portion (particularly hollow body 2) that should be pointed out that feed conduit 1 or 1' can have with here shown in the different shape of tubular in shape, for example it can be prism shape roughly.

Also for hollow body 2, it can be by made, for example (as limiting examples) steel, stainless steel, aluminum alloy, titanium alloy etc., the optional material of the type that perhaps is adapted at using in the chemical erosion environment, for example stupalith.

According to another version; It may be embodied as optional embodiment or makes up with an above-mentioned embodiment; It is contemplated that the use control circuit, this control circuit comprises or controls at least one temperature transducer, particularly with feed conduit 1 respectively export 4 and/or the temperature transducer that is associated of entry port 3,3'; So that control the temperature of the inner fuel of feed conduit at least, thereby overcome the defective of using in the prior art, control based on the time.

Selectively, said at least one temperature transducer part that can be Preheating unit; For example, it can be installed on the body 2, is perhaps directly obtaining near said outlet 4 and/or near the zone of entry port 3,3' through deposition.

Also preferably can use the heating system that comprises at least one feed conduit and the above-mentioned

type

5A, 5B electric heater (heater perhaps even not of the same type), this heating system comprises the control of so-called pulse duration modulation (PWM) type.

This control is widely used in the prior art regulates the electric power supply with the load in the transducer for example, so that regulate the speed of d.c. motor.Therefore, its basic principle is no longer carried out any introduction here; Further detailed description should be with reference to the technology and the scientific literature of this theme.

In this example, said modulation can be that function is regulated with the temperature that is detected by one or more temperature transducers, and this temperature transducer detects fuel temperature or (more generally) reference temperature, for example ambient temperature.Selectively, said modulation can be regulated with time or the different seized function that is measured as.

Therefore, can use the for example electronic circuit of microcontroller type, preferably be provided with the electronic circuit of storage arrangement; Reference value can be determined in the said circuit and/or in the said storage arrangement in advance; Especially for correspondingly changing modulation value, for example therefore through detecting an amount or temperature, checkout value and predetermined value comparison and calculating being used to control said PWM modulation or circuit control value.

Through using such control, can reduce the energy consumption of electric heater, simultaneously the preheating speed there is not adverse effect, perhaps can optimize the operation of motor, particularly aspect fuel consumption and/or toxic emission.

According to going back a possibility instance, system comprises control unit, and this control unit receives the temperature value of being read by one or more sensors in its input device, for example from being arranged in feed conduit temperature inside sensor; Preferably, this scheme provides the direct monitoring of fuel temperature.

Selectively, it is contemplated that and use the temperature transducer be installed in other position, for example be installed in the branch conduit, near sparger etc.

Like this, power percentage that control unit can be supplied with and/or power are that function is in time confirmed with the temperature, so that overcome the problem of the indirectly controlled system that uses in the prior art, this indirectly controlled system is based on the operating time of heating element.

Through using PWM control, in fact can realize a kind of method of coming pre-heating fuel of being used for, so that strict restriction about the energy consumption of fuel heating, is perhaps optimized the fuel heating for the optimum operation of vehicle motor with by the voltage of management and control.

According to the method for the invention; In fact; When control unit receive at its input device place the expression cold engine signal (for example by be positioned on the motor sensor to signal, this sensor for example detects under the ethanol situation and is lower than 10 ℃ temperature, is lower than 5 ℃ temperature especially) time; Execution is supplied with the step of heating element with peak output, so that rapidly pre-warming fuel; At this on the one hand, must be pointed out that also this temperature can change, because they depend on the type of the fuel of use to a great extent.

When after control unit receive the expression thermo-motor secondary signal (for example by the signal that is positioned at the sensor on the motor; This sensor is higher than 60 ℃ temperature; Preferably near 80 ℃ temperature) time, control through aforementioned PWM and to reduce power output.

Represented an also version among Figure 16: in this example,, be furnished with packing ring 94B, for example O shape ring etc. in order to improve the sealing between hollow lining 72B and pin 73B.

Said packing ring 94B between hollow lining 72B and pin 73B and near its end sections, and preferably with fixed in insulator 77B connect.

The attendant advantages that provides by this version be protection fixed in insulator 77B avoid possible fuel infiltration, therefore fixed in insulator 77B can make by the material that is not suitable for bearing from the chemical erosion of fuel.

Although in above-mentioned instance; Purpose for the sake of simplicity, preferred feature of the present invention are introduced each other in combination, but; They can be independently or implement alternatively, because they also can be used for and different device and the systems of device or system through non-sex-limited case introduction here.

Claims

1. an electric heater (5A, 5B) that is used for the fuel of suction engine comprises at least one fire end (6B), and this fire end is suitable for inserting the hollow body (2) of the device (D) that is used for heating said fuel;

It is characterized in that: said electric heater (5A, 5B) has the structure that comprises at least one electrical heating elements and a terminal (8B); This terminal (8B) is used for to said heater (5A, 5B) power supply, and said structure is suitable for when carrying out best coupling and/or operate when being associated with said hollow body (2).

2. electric heater according to claim 1 (5A, 5B); It is characterized in that: be used for being suitable for being associated at least in part with the hole or the seat (25B, 26B) of said hollow body (2) to the terminal (8B) of said heater (5A, 5B) power supply, and preferably at least in part by the plastic materials manufacturing.

3. electric heater according to claim 1 and 2 (5A, 5B); It is characterized in that: this electric heater comprises spacer element (7B); This spacer element comprises at least one metalwork especially; This metalwork is preferably used in interface region coupling with at least one parts of plastics of said terminal (8B), and this interface region for example is included in the interface region in the sealed environment.

4. electric heater according to claim 3 (5A, 5B); Wherein: said sealed environment is limited on first packing ring (10B) and second packing ring (11B) at least in part; This first gasket arrangement is between the said metalwork and said hollow body (2) of said spacer element, and this second gasket arrangement is between the said parts of plastics and said hollow body (2) of said terminal.

5. electric heater according to claim 4 (5A, 5B), wherein: said first packing ring (10B) and said second packing ring (11B) have different-diameter.

6. according to any one or multinomial described electric heater (5A, 5B) in the claim 2 to 5, wherein: said terminal (8B) comprises at least one, preferably two electric conductor (83', 83 ").

7. according to any one or multinomial described electric heater (5A, 5B) in the claim 2 to 6; Wherein: said terminal (8B) comprises plastic body (81B); This plastic body is preferably through coating molded the acquisition, and particularly (it is molded that 83', 83 ") goes up coating at said at least electric conductor.

8. according to aforementioned any one or the described electric heater of omnibus claims (5A, 5B); Wherein: said electric heater (5A, 5B) or said terminal (8B) comprise the housing (23B) that is used for fixing device, and this fixing device makes electric heater or said terminal can be fixed on the said hollow body (2).

9. according to any one or multinomial described electric heater (5A, 5B) in the claim 1 to 5; Also comprise: basic tubular shell (61B) and be contained in the electric winding (62B) in the said shell (61B); Said electric winding (62B) electrically contacts with said shell (61B); Said heater (5A, 5B) also comprises pin (73B), and this pin part ground inserts in the said shell (61B), and electrically contacts with said electric winding (62B); Wherein, said shell (61B) and said pin (73B) are arranged in ring (78B) in fixed between this pin and the shell (61B) and electrical insulation through the body around pin (73B).

10. according to any one or multinomial described electric heater (5A, 5B) in the claim 2 to 9; Wherein: said heater (5A, 5B) comprises hollow lining (72B); This hollow lining is adapted such that the shell (61B) that holds electric winding (62B) is connected with the plastic body of said terminal (8); Said shell (61B) and said hollow lining (72B) hold pin (73B); Said pin through ring (78B) in fixed with respect to said hollow lining (72B) electrical insulation with fixed in, during this is fixed ring be arranged in pin (73B), with the opposite place, end, end that is contained in the said shell (61B).

11. according to aforementioned any one or the described electric heater of omnibus claims (5A, 5B); Also comprise: at least one electrical heating elements; This electrical heating elements comprises the first electric winding part (630B) and the second electric winding part (631B); Wherein, the said second electric winding part (631B) is positive temperature coefficient (PTC) resistor.

12. according to aforementioned any one or the described electric heater of omnibus claims (5A, 5B), wherein: electrical heating elements is through having diameter D _FilElectric wire twine with pitch P and the electric winding (63B) that obtains, this winding has number of stitches N _Sp, wherein, shell (61B) is basic tubular, and has D outer diameter _Inv, and wherein satisfy at least one following condition:

N _Sp/ P>2, N preferably _Sp/ P>4;

P<6mm

3<d _Inv/ D _Fil<10, preferably 5<d _Inv/ D _Fil<7.

13. according to any one or multinomial described electric heater (5A, 5B) in the claim 1 to 12, it is suitable for being associated with pulse duration modulation (PWM) control system or being controlled by pulse duration modulation (PWM) control system.

14. a fuelizer (D) that is used for the heat absorbing type motor, comprising: feed conduit (1), this feed conduit comprise hollow body (2), and this hollow body is equipped with at least one fuel inlet (3,3') and at least one fuel outlet (4);

It is characterized in that this heating equipment comprises that also at least one is according to aforementioned any one or the described electric heater of omnibus claims (5A, 5B).

15. heating equipment according to claim 14 (D); It is characterized in that: said hollow body (2) comprises at least two holes (21A, 21B); This hole is sealed respectively by two electric heaters (5A, 5B) under assembly condition, and these two electric heaters (5A, 5B) are associated with said hollow body (2) through the shape coupling.

16. according to claim 14 or 15 described heating equipments (D); It is characterized in that: said at least one electric heater (5A, 5B) comprises at least one electrical heating elements (63B, 630B) that is arranged in the said hollow body (2); And said hollow body (2) comprises a plurality of fuel outlets (4), and said electrical heating elements (63B, 630B) extends between two adjacent outlets (4).

17. a fuel-feed conduit (1) that is used for the heat absorbing type motor comprises at least one hollow body (2), this hollow body is equipped with at least one fuel inlet (3,3') and at least one fuel outlet (4);

It is characterized in that:

This feed conduit comprises at least one fixing device (28B) and/or seat (25B, 26B), is used for fixing and/or holds according to any one or multinomial described electric heater (5A, 5B) in the claim 1 to 13.